Takes place after the final defeat of the Dinosaur Empire and the death of Musashi Tomoe in the original Getter Robo series. Dr. Saotome, creator of Getter Robo, fears that the peace the Getter Robo team has won will be short lived and that an even greater enemies would appear. Dr. Saotome's fears are justified when the militaristic Hyakki (or "Hundred demons") Empire appears, but Dr. Saotome is prepared with the creation of an even more powerful Getter Robo, Getter Robo G and a new Getter Robo base. Also with Musashi Tomoe dead, Dr. Saotome needs a third pilot which he finds in baseball player Benkei Kuruma. (Source: Wikipedia)

Kagemori Mamoru is a dowdy boy whose hair is disheveled and who wears thick glasses, but he is actually the son of a ninja family. They have protected their neighbors, the Konnyaku family, secretly for 400 years. Mamoru has personally protected their daughter, Konnyaku Yuuna, since they were in kindergarten. When Yuuna is in trouble, Mamoru puts on ninja suit and turns into a competent ninja to help her.

Rushuna is a blonde and very beautiful Senshi (gun expert) that travels through the world with one purpose. Which is to make the world a peaceful place by, instead of fighting with weapons, taking away the people's will to fight by giving them a smile. Although she doesn't want to fight, she is forced to, and shows amazing gun skills. In this journey she meets Yajirou, a mercenary that uses a sword to fight and joins her on her journey. (Source: ANN)

Dr.Haneda was developing experimental giant robot warriors to fight the allies during the Second World War, but before his creations could see action, Allied bombs destroyed the facility and killed him. A decade later criminals discovered two of the surviving prototypes, #26 and 27 in the series, and used the remote controlled robots to commit a number of crimes. Young Shotaro Haneda, the twelve year old son of Dr.Haneda, did some investigating and discovered that the mob were hunting for the twenty-eighth robot in the series, rumoured to be the most powerful of them all. Racing the villains, Shotaro discovers the robot first, along with Dr.Shikashima, a colleague of his father's who was also believed killed by the Allied bombing. Together the two prevent Tetusjin-28 (the robot's official designation) from falling into the hands of the bad guys, and decide to dedicate him to peace rather than war. Shotaro fought crime for a long time, supported by Dr.Shikashima, who would repair Tetsujin-28 when he was damaged, and by police officer Otsuka. Shotaro even battled the alien Magmans, invaders from the planet Magma, who came to Earth late in his career, bringing their own giant robots, Magma X and Gold Wolf, with them. (Source: AniDB)